Three light sticks are activated at the same time. one stick is placed in a beaker of hot water, one in a beaker of ice water, and one remains at room temperature. which is the likely result? a) the hot stick is brightest, and the cold stick is dimmest. b) the sticks in water are brighter than the one in the room air. c) the hot stick is dimmest, and the cold stick is brightest.

Option (A) is the correct answer.

Explanation:

It is known that rate of a reaction depends upon temperature. This means that more is the temperature more will be the kinetic energy of particles.

Hence, this will cause greater number of collisions between the particles. As a result, rate of reaction will become faster.

Thus, we can conclude that the result for the given situation will be that the hot stick is brightest, and the cold stick is dimmest.

part 1: the half-life of the element is 22 years.

part 2: it will take 132.02 year for the sample to decay from 308.0 g to 4.8125 g.

explanation:

part 1: there are two ways to determine the half life time.

first way: the half life time can be determined directly from its definition as it is the time required for the sample to decay to its half concentration.

from the data the initial concentration was 45.0 g and decayed to its half value (22.5 g) in 22.0 years.

second way: the radio active decay is considered first order reaction so we can use the laws of first order reactions.

k = (1/t) ln (a/a-x), where k is the rate constant of the reaction,

t is the time of the reaction

a is the initial concentration of the reactant

a-x is the remaining concentration at time (t)

a = 45.0 g the initial concentration at t = 0 year.

at t = 22 year, a-x = 22.5 g

then k = (1/22 year) ln (45.0 g/ 22.5 g) = 0.0315 year-1.

the half-life time (t1/2) = ln 2/ k = 0.693/ k =0.693/ 0.0315 = 22 years.

part 2:

using the same law k = (1/t) ln (a/a-x),

using the given data; a = 308.0 g and a-x = 4.8125 g and the calculated k from the part 1 (k = 0.0315 year-1)

t = (1/k) ln (a/a-x) = (1/0.0315) ln (308.0/ 4.8125) = 132.02 years

hloride, what is the mass of calcium in

explanation: